Function split_quoted_identifier_inner 

pub fn split_quoted_identifier_inner(
    name: &str,
    open: char,
    close: char,
) -> Option<Vec<String>>

Splits a .-separated name into its identifiers. An identifier wrapped in open and close may contain ., and a doubled close inside it stands for one close, e.g. "a.b" and "a""b" for Postgres, [a.b] and [a]]b] for SQL Server. Returns None if the name is malformed.